Image sensor calibration

1. A method of calibrating an image sensor, comprising: detecting a response from a pixel of the image sensor as a result of light having an intensity impinging on the pixel; receiving an actual standard deviation of the response of the pixel at the intensity of light; determining an averaging number for the pixel at the intensity, the averaging number being a number of responses of the pixel at the intensity to be averaged to attain an average response having a standard deviation less than or equal to a target value; and determining the average response of the pixel using the determined averaging number, wherein determining the averaging number includes rounding the determined averaging number to the closest higher power of two.

2. The method of claim 1 , wherein receiving the actual standard deviation includes determining the actual standard deviation of the response of the pixel at multiple intensities of incident light and recording the determined actual standard deviations.

3. The method of claim 1 , wherein determining the actual standard deviation includes determining the actual standard deviation for multiple pixels of the image sensor at multiple intensities of incident light and recording the determined actual standard deviations.

4. The method of claim 3 , wherein determining the averaging number includes determining an averaging number for each of the multiple pixels, the averaging number for each pixel of the multiple pixels being the number of the responses of the pixel to be averaged to attain an average response for the pixel at the intensity of light incident on the pixel.

5. The method of claim 1 , wherein determining the averaging number includes determining the averaging number using the equation n = ceil ⁡ ( σ actual σ target ) 2 , where n=the averaging number, σ actual =the actual standard deviation at the intensity, σ target =the target value of standard deviation, and ceil is a ceiling function that rounds a result of (σ actual /σ target ) 2 to the next integer greater than or equal to the result of (σ actual /σ target ) 2 .

6. The method of claim 1 , wherein the rounding includes rounding the determined averaging number using the equation n*=2 {ceil[log 2 (n)]} , where n*=the averaging number rounded to the closest higher power of two, n=the determined averaging number, and ceil is a ceiling function that rounds a result of the calculation of n*=2 {ceil[log 2 (n)]} to the next integer greater than or equal to the result of the calculation of n*=2 {ceil[log 2 (n)]} .

7. The method of claim 1 , wherein the target value of standard deviation is the actual standard deviation of a pixel of the image sensor having a lowest value of response.

8. The method of claim 1 , wherein the target value of standard deviation is 1 DN.

9. A control system for an image sensor, comprising: the image sensor including a plurality of pixels arranged thereon, each pixel of the plurality of pixels being configured to output a response indicative of an intensity of light incident thereon; a memory including a database, the database including an averaging number for at least one pixel of the plurality of pixels at multiple intensities, the averaging number being indicative of a number of responses of the pixel at an intensity to be averaged to attain an average response having a standard deviation less than or equal to a target value; and a processor operatively coupled to the image sensor and the memory, the processor being configured to determine the average response of the pixel based on the determined averaging number and the intensity of light incident on the pixel, wherein the database includes the averaging number rounded to the closest higher power of two.

10. The control system of claim 9 , wherein the database includes the averaging number for each of multiple pixels of the plurality of pixels.

11. The control system of claim 10 , wherein the processor is configured to determine the averaging number for the multiple pixels, the averaging number for each pixel of the multiple pixels being the number of the responses of the pixel to be averaged to attain an average response for the pixel at the intensity of light incident on the pixel.

12. The control system of claim 9 , wherein the database includes the averaging number obtained using the equation n = ceil ⁡ ( σ actual σ target ) 2 , where n=the averaging number, σ actual =the actual standard deviation at the intensity, σ target =the target value of standard deviation, and ceil is a ceiling function that rounds a result of (σ actual /σ target ) 2 to the next integer greater than or equal to the result.

13. The control system of claim 9 , further including an endoscope coupled to the image sensor.

14. A method of operating an image sensor, comprising: detecting a response from a pixel of the image sensor as a result of light having a first intensity impinging on the pixel; obtaining an actual standard deviation of the response of the pixel at the first intensity, the actual standard deviation being a number indicative of an expected variation in the response of the pixel; determining a number n at the first intensity, wherein the number n is the number of frames at the first intensity to be averaged to attain a target standard deviation for the response at the first intensity, wherein determining the number n includes determining the number n using the equation n = ceil ⁡ ( σ actual σ target ) 2 , where n=the number n, σ actual =the actual standard deviation at the first intensity, σ target =the target standard deviation and ceil is a ceiling function that rounds a result of (σ actual /σ target ) 2 to the next integer greater than or equal to the result of (σ actual /σ target ) 2 ; and averaging n number of responses from the pixel at the first intensity to obtain an average response from the pixel at the first intensity.

15. The method of claim 14 , further including detecting a response from the pixel as a result of light having a second intensity impinging on the pixel, determining the number n at the second intensity, and averaging n number of responses from the pixel at the second intensity to obtain an average response from the pixel at the second intensity.

16. The method of claim 14 , wherein obtaining the actual standard deviation includes receiving the actual standard deviation from a memory operatively coupled to the image sensor.

17. The method of claim 14 , wherein determining the number n is performed via a processor operatively coupled to the image sensor.

18. The method of claim 14 , wherein detecting the response includes detecting the response from the image sensor of an endoscope.